Pulse counter having plural discrete counter indication means



Oct. 19, 1965 J. A. HAWLEY 3,213,374

PULSE COUNTER HAVING PLURAL DISCRETE COUNTER INDICATION MEANS Filed May 17. 1960 2 Sheets-Sheet l IN VEN TOR.

E- James /7 b dwiey BY W /7 arms/4 Oct. 19, 1965 J. A. HAWLEY 3,213,374

PULSE CUUNTER HAVING PLURAL DISCRETE COUNTER INDICATION MEANS Filed May 17, 1960 2 Sheets-Sheet 2 INVENTOR.

United States Patent 3,213,374 PULSE COUNTER HAVING PLURAL DISCRETE COUNTER INDICATIUN MEANS James A. Hawley, Milford, Mich., assignor to Weltronic Company, Southiield, Mich., a corporation of Michigan Filed May 17, 1960, Ser. No. 29,672 7 Claims. (Cl. 32848) This invention relates to counters and more particularly to systems for timing events by counting a series of relatively constant-frequency pulsations.

An object of this invention is to produce an output indication at the termination of each of a plurality of polydigit counts.

Another object of this invention is to improve the accuracy with which a counting system is automatically reset at the termination of the last of a series of polydigit counts.

Another object of this invention is to improve the accuracy of ascertaining the arrival of a cascaded counter at a preselected count.

Another object of this invention is to improve the accuracy of producing stepping of a counting device in response to sinusoidal input signals.

The manner of accomplishing the foregoing objects and other objects and features of the invention will become apparent from the following detailed description of an embodiment of the invention when read with reference to the accompanying drawings in which:

FIG. 1 is a schematic representation of a portion of a timing system embodying the principles of the present invention; and

FIG. 2 is a schematic representation of another portion of the system of FIG. 1, and should be placed to the right of FIG. 1 for proper orientation.

The program timer of FIGS. 1 and 2 comprises a driving amplifier V4, a plurality of timing amplifiers V5, V12A, V12B, a plurality of counter tubes V1, V2, and V3, and a plurality of coincidence circuits including thyratrons V6, V7, V8, V9 and V10. In these circuits, a source of direct voltage is represented as a circle, and it is to be understood that the other terminal of each such illustrated source is connected to ground.

The counters V1, V2 and V3 are representatively illustrated to be cold cathode glow transfer or stepping tubes which may, for example, be of the type manufactured by Ericson Telephone Ltd., of Great Britain, type GS10C. These tubes are commercially available in the United States of America. In general, each of these stepping tubes, such as stepping tube V1, comprises a plurality of cathodes designated 1-10, inclusive, an anode 200 common to all those cathodes, and a first and second plurality of intermediate, transfer or guide electrodes interposed the main cathodes Nos. 1-10. Since the electrodes in each of these groups of intermediate electrodes are electrically interconnected, the two groups of electrodes are, for convenience of illustration, designated as single electrodes 211 and 212.

The anode 200 is connected through resistor R to a source of positive direct potential on conductor 215, the main cathodes Nos. 1-9 are connected to ground through individual load resistors R29-R37, and main cathode No. 10 is connected to zero line 217 through resistor R38. The tube is designed so that with the properly selected value of resistor R15, discharge can be supported, at any one time, between the anode and but one of the main cathodes Nos. 1-10 so that the tube will commutate. The discharge path is advanced so that it exists between the anode and the successive cathodes by applying suitable pulses to the transfer or guide electrodes 211 and 212, the

direction of advance being selected by the sequence of pulsing of those two groups of electrodes.

In the disclosed arrangement, the tube is initially set so that conduction exists between anode 200 and main cathode No. 10, and the discharge path is advanced from cathode to cathode in numerical order, the discharge first transferring from cathode No. 10 to cathode No. 1, thence to cathode No. 2 and so forth. This is accomplished by applying a pulse to transfer electrodes 212 slightly in advance of the application of a pulse to transfer electrodes 211. It will be appreciated that other forms of counting devices may be employed, that other forms of cold cathode gaseous discharge counting tubes may be employed, and that if the direction of discharge advance is established inherently in the tube by the construction and configuration of the cathodes or otherwise, the necessity for providing two time-phased input pulses can be avoided.

As will be seen, the function of tube V1 and of the other counter tubes disclosed, is to count a plurality of serially received input pulses and to transmit output signals whenever selected numbers of those pulses have been received. The sixty-cycle alternating line source is utilized as a pulse source in the present system so that the counters in effect count cycles of the sixty-cycle line frequency.

Prior to the closure of switch SW11, relay CR1 is released and its contacts CRlc are open. Consequently, a potential of approximately 150 volts negative (relative to ground) is applied to the zero line 217. As a result, the No. 10 cathodes of the counter tubes V1, V2 and V3 are returned to a source of quite negative potential relative to the ground potential to which the other cathodes of those tubes are returned. This selective application of a high negative potential to the No. 10 cathodes, in conjunction with the application of the high negative potential to the other elements connected to the zero line (as will become apparent from the ensuing description) results in each of the counter tubes being initially set to a condition in which the conduction exists between the anode and the No. 10 cathode thereof.

When line switch SW11 is closed, the source of alternating potential S5 is connected across the primary windings of transformers T1 and T2, with no present operational effect. However, when the initiating switch or cont-acts IS are closed, the energizing circuit for relay CR1 is completed and that relay operates. Relay CR1, upon operating, closes its contacts CRla to connect a positive direct voltage to conductor 216 over which it is supplied through load resistor R7 to the anode of thyratron V4, through resistor R65 and the winding of relay CR2 to the anode of thyratron V6, through resistor R70 and the winding of relay CR3 to the anode of thyratron V7, through resistor R and the winding of relay CR4 to the anode of thyratron V8, through resistor R and the winding of relay CR5 to the anode of thyratron V9, through resistor R and the winding of relay CR6 to the anode of thyratron V10, and across a voltage divider circuit to be described. Relay CR1, in operating, also closes its contacts CRIc to connect the zero line to ground to relieve the normalizing signals and enable the circuit to operate.

When the circuit is in operation, pulses derived from the alternating voltage supply are applied to the transfer electrodes of the counter tube V1 by means including tube V5. Tube V5 is a pentode the cathode and Sup pressor grid of which are grounded, the anode 'of which is connected through plate resistor R11 to a positive di rect voltage on conductor 215 and the screen grid of which is connected through the secondary Winding of transformer T2 in series with resistor R3 to a source of negative potential indicated on the drawings to have a magnitude of a negative volts. Transformer T2 is preferably a peaker type transformer in which the core has an air gap so that there will be no effective non-conductive.

signal, even if other conditions are met.

breakdown of fiux thereacross until the voltage ap pearing across the primary winding reaches a preselected value. This feature, coupled with the application of a large negative biasing voltage through resistor R3, resultsin the application of a positive pulse of energy to the screen grid of vacuum tube V5 at, or approximately at, the 90 point on the positive half-cycle of the alternating voltage wave form appearing across the primary winding of, transformer T2. However, for reasons that will become apparent hereinafter, it is desirable that no such pulses be applied to the screen grid of tube V5 unless the coincidence circuit including thyratron V is Therefore, the screen grid of tube V5 is connected through resistor R8 to the anode of thyratron V10. If thyratron V10 is conductive, its anode potential is lower than the potential on conductor 216 due to the drop across resistor R85 and the winding of relay CR6, and the algebraic sum of the negative one hundred volt potential applied through resistor R3, of the relatively low positive potential applied through resistor R8, and of the positive pulse developed across the secondary winding of transformer T2 is not sufficient to cause vacuum tube V5 to produce the requisite output However, if thyratron V10 is extinguished, the positive potential at its anode is substantially equal to the positive potential on conductor 216 and the resultant voltage is applied through resistor R8 to the screen grid of vacuum tube V5 and is such that the algebraic sum of the voltages applied to that screen grid at the positive peak of the voltage developed across transformer T2 is sufficient to actuate tube V5. Thus, non-conductivity of thyratron V10 is a condition precedent to the effective operation of vacuum tube V5.

The circuits connected to the control grid of tube V5 also establishes another condition precedent to its effective operation. Thus, that control grid is connected to a source of negative potential (representatively negative 20 volts) through the resistance network comprising resistors R9 and R10, and is connected to ground through the cathode resistor R6 of thyratron V4 and uni-directional current conducting device RE19. When thyratron V4 is non-conductive, therefore, a negative bias is applied between the control grid and cathode of vacuum tube V5 to prevent the effective production of output signals by that tube.-

Thyratron V4 is initially disabled because its plate circuitis open at contact CRla of relay CR1. When relay CR1 operates, closing contacts CRla, the output circuit of thyratron V4 is energized, but thyratron V4 will not immediately fire due to a provision of a short time delay to ensure that relay CR1 has operated and that any chattering of its contacts have dissipated to prevent any improper operation of vacuum tube V5. Thus, the alternating voltage applied across the primary winding of transformer T1 upon the closure of switch SW11 will induce an alternating voltage across the secondary winding of that transformer which is applied across serially interconnected resistors R1 and R2. The voltage across resistor R1 is half-wave rectified by means including rectifier REl, which is connected in series with normally-closed contacts CRlb of relay CR1. This rectified voltage is filtered by and developed across resistor R4 in parallel with capacitor C1, and the polarization of rectifier RE1 is such that the right hand terminal contacts CRlb, the rectifying circuit including rectifier RBI is disabled, but a holdoif voltage will continue to be applied to the control grid of thyratron V4 until capacitor C1 is adequately discharged through resistor R4. When the charge on capacitor C1 is dissipated to a preselected value, thyratron V4 will be fired as the alternating voltage across resistor R2 increases in a positive direction. In the preferred arrangement, transformers T1 and T2 are so connected that the voltage at the upper end of the secondary winding of transformer T2 is out of phase with voltage at the upper end of the secondary winding of transformer T1. Thus, thyratron V4 will be fired during a half cycle of the supply during which no positive pulse is being applied to the screen grid of tube V5. In this fashion, thyratron V4 is fired approximately 180 before the next positive pulse will be applied to the screen grid of tube V5.

When thyratron V4 fires, the potential at its cathode rises due to the potential drop across resistor R6, correspondingly raising the potential at the junction of resistors R9 and R10 and thereby applying a voltage to the tube V5 which will enable that tube to operate in response to the positive pulses applied to its screen grid. After the foregoing conditions precedent to the effective operation of vacuum tube V5 are met, a negativegoing pulse will appear at the anode of tube V5 at each positive pulse supplied to the screen grid thereof. These negative-going pulses are applied through capacitor C4 and through serially interconnected resistors R12 and R14 to a source of relatively low positive potential. Since transfer cathodes 212 are connected at the junction of resistors R12 and R14, their potential will be sharply reduced at each such pulse, producing a transfer of the discharge within the counter tube V1 so that it exists between the anode 200 and the transfer electrode 212 which is adjacent the last conducting cathode, in the initial condition, cathode No. 10.

Each of the series of negative-going pulses at the anode of tube V5 is further applied through capacitor C4, resistor R13, and capacitor C6 to ground, with the transfer electrodes 211 being connected to the junction of resistor R13 and capacitor C6. The time constant of the network including elements R13 and C6 is selected so that the application of a negative-going pulse to the transfer electrodes 211 will be delayed for an appropriate interval relative to the time that the'pulses are applied to' the transfer electrodes 212. At each such application, the discharge path in tube V1 is transferred so that it exists between the anode 200 and the next adjacent transfer electrode 211 and, upon the termination of the negative pulse to transfer electrode 211, conduction is established between anode 200 and the next succeeding main cathode, following initial condition, cathode No. 1. Successive pulsing of transfer electrodes 212 and 211 will cause the conductive path to advance along the series of main cathodes. 1

At the tenth input pulse, the conductive path will be transferred so that it exists between the anode 200 and the No. 10 cathode of units counting tube V1. The resultant sudden increase in the potential at that cathode results in the application of a positive pulse to the control grid of vacuum tube V12A'via the network comprising capacitor C8 and resistor R17. In response thereto, vacuum tube V12A will apply a negative pulse to transfer electrodes 222 of the tens counter V2 by means of the network including capacitor C9 and resistors R19 and R21 and will, a short delay thereafter, apply a negativegoing pulse to the transfer electrodes 221 of the counter tube V2 by means including capacitors C9 and C11 and resistor R20. In response to these time-spaced pulses applied to transfer electrodes 222 and 221 of the tens counter tube V2, the conductive path therein will be transferred so that it exists between the anode and the No, '1 cathode thereof.

The next succeeding or eleventh input pulse will cause the conductive path in the units counter tube V1 to again step to the No. 1 cathode of that tube and succeeding pulses will cause the units tube V1 cyclically to count. Each time that the conductive path in the tube includes the No. cathode of that tube, an output or carry pulse will be transmitted to advance the conductive path in the tens counter tube V2 one step.

At the hundredth input pulse, the conductive path in the tens tube V2 will be advanced to exist between the anode and the No. 10 cathode thereof, which will cause a positive pulse to be applied to the control grid of tube V12b which will result in the application of a counting signal to the hundreds counter tube V3 in a manner similar to that above described. In this fashion, onethousand input pulses can be counted by providing units, tens and hundreds counter tubes cascaded as illustrated.

Each of the cathodes of the units counter tube V1 is connected to each corresponding stationary contact of each of a plurality of selector switches SW1, SW4, SW7, SW10 and SW13, each of the main cathodes .of the tens counter tube V2 is connected to a corresponding one of the stationary contacts of a plurality of selector switches SW2, SW5, SW8, SW11 and SW14, and each of the main cathodes of the hundreds tube V3 is correspondingly connected to each corresponding stationary contact of each of a plurality of selector switches SW3, SW6, SW9, SW12 and SW15.

The coincidence circuits including thyratrons V6-V10 serve to detect the concurrence of conductivity at each of three selected main cathodes of the three counter tubes V1, V2 and V3. Thus, each of the thyratrons V6-V10 will be fired at an individually preselectable count. Each of these coincidence circuits, such as the coincidence circuit including thyratron V6, includes three unidirectional current conducting devices such as diodes RE4, RES and RE6 which may be characterized as the units, tens, and hundreds diodes in that they are connected through the stepping switches to selected cathodes of the units, tens and hundreds counter tubes V1, V2 and V3. Diode RE4 is connected to the wiper of selector switch SW1 which, in the illustrated setting, is connected to the No. 4 stationary contact of that selector switch and hence is connected to the No. 4 cathode of counter tube V1. Diode RES is connected to the wiper of selector switch SW2, which in the illustrated setting is connected to the No. 3 contact of that switch and hence to the No. 3 cathode of the tens counter tube V2, and diode RE6 is connected to the wiper of switch SW3 which is shown to be positioned in association with the No. 2 con-tact thereof and hence is connected to the No. 2 main cathode of tube V3. As a result, in the illustrated settings, thyratron V6 is arranged to be fired at the two-hundred and thirty-fourth input pulse. The setting, of course, is purely arbitrary and may be varied as desired in accordance with the timing functions sought to be performed.

Similarly, the diodes RE7, RES and RE9 are associated with selector switches SW4, SW5 and SW6 so that thyratron V7 will be fired, as a representative example, at a different preselected total count of the input pulses. Thyratrons V3, V9 and V10 are also elements of coincidence circuits including individual diodes connected to individual selector switch banks in a corresponding fashion.

Since relay CR1 is operated, a circuit is completed from a source of positive 200 volt potential, through contacts CRla, conductor 216, resistor R59, and resistor R60, to ground through contacts CR1c. As a result, a positive potential appears at conductor 241. At any time that the main cathode to which diode RE4, RES, or RE6 is not an element of the conductive path in that counter tube, that cathode is essentially at ground potential and current will flow from conductor 241, through resistor R61, through that diode, to that cathode and to ground through the cathode resistor. In the preferred arrangement, resistor R61 has a quite high value of resistance so that the voltage appearing at the cathodes of the diodes RE4-RE6 under this circumstance is quite low. This relatively low positive potential is applied in series with a negative 20 volt potential across voltage dividing resistors R97 and R62 and the resultant voltage appearing at the junction of resistors R97 and R62 is applied through current limiting resistor R63 to the control grid of thyratron V6. The magnitude of this potential is insufiicient to fire thyratron V6, and the parameters of the circuits are selected so that the potential applied to the control grid of thyratron V6 will not be adequate to permit that thyratron to fire as long as the cathode to which any one of the rectifiers RE4-RE6 is connected is not an element of the conductive path in the associated counter tube. Therefore, in the illustrated arrangement, at but only at the preselected count, all three of the countertube cathodes to which the diodes RE4-RE6 are then selectively connected are supporting conduction and are at a potential which is positive relative to ground. As a result, rectifiers RE4-REG will present an appreciably higher impedance to the flow of current from conductor 241 through resistor R61 via the previously traced circuits. The voltage drop across resistor R61 will accordingly fall and the potential applied to the control grid of thyratron V6 will correspondingly rise to a value sufiicient to fire that thyratron. When thyratron V6 fires, relay CR2 included in its plate circuit, will be energized and will remain energized until relay CR1 is released.

In a similar manner, thyratron V7 .will vbe fired at a preselected count to operate relay CR3, thyratron V8 will be actuated at a preselected count to operate relay CR4, thyratron V9 will be actuated at a preselected count to operate relay CR5, and thyratron V10 will be actuated at a preselected count to energize relay CR6. Thus, the several timing functions are all initiated at the same instant and the numbers of pulses to which those several thyratrons are set to operate are concurrently counted up to the point of the count selected for each of those thyratrons.

The sharp reduction in plate potential of thyratron V10 resulting 'from the conductivity thereof, is applied to resistor R8 to terminate the operation of vacuum tube V5. This terminates operation of the counting circuit. Therefore, while the contacts of relays CR2-CR6 may be connected in any fashion to perform any desired function, and while there is no necessary order in which those relays become operated, resistor R8 should be connected to the anode of the last one of the employed thyratrons which is to be fired. With the illustrated connection, it is assumed that relay CR6 is to operate at the highest count.

While it will be apparent that the embodiment of the invention herein disclosed is well calculated to fulfill the objects of the invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. A timing system for counting input pulses and for producing output indications at each of a plurality of preselected numbers of said pulses which are concurrently counted comprising a source of regularly recurring signals, pulse means connected to said source for producing a series of input signals from said regularly recurring signals, plural stage counting means responsive to said input signals for counting numbers as large as the largest of said preselected numbers comprising first counting means responsive to said input signals for repetitively and cyclically counting predetermined numbers of said input pulses and producing a discrete individual output indication at each count and an output signal at each of said predetermined numbers of input pulses and second counting means connected to said first countnig means for repetitively and cyclically counting predetermined numbers of said output signals and producing a discrete individual output indication at each count, first and second output devices, control means including a first coincidence circuit having an element individual to and connected to each of said first counting means and said second counting means and responsive at each concurrence of preselected discrete individual output indications from said plural stage counting means including said first and second counting means for operating said first output device, control means including a second coincidence circuit having an element individual to and connectedto each of said first counting means and said second counting means and responsive at each concurrence of different preselected discrete individual output indications from said plural stage counting means including said first and second counting means for operating said second output device, and means effective only after said plural stage counting means has counted a number of said input signals equal to that required to cause said plural stage counting means to produce the larger of said preselected discrete output indication and said different preselected output indication for disabling said pulse means to produce said series of input signals.

2. A timing system for counting input pulses and for producing output indications at each of a plurality of preselected numbers of said pulses which are concurrently counted comprising a source of regularly recurring signals, pulse means connected to said source for producing a series of input signals from said regularly recurring signals, plural stage counting means responsive to said input signals for counting numbers as large as the largest of said preselected numbers comprising first counting means responsive to said input signals for repetitively and cyclically counting predetermined numbers of said input pulses and producing a discrete individual output indication at each count and an output signal at each of said predetermined numbers of input pulses and second counting means connected to said first counting means for repetitively and cyclically counting predetermined numbers of said output signals and producing a discrete-individual output indication at each count, first and second output devices, control means including a first coincidence circuit having an element individual to and connected to each of said first counting means and said second counting means and responsive at each concurrence of preselected discrete individual output indications from said plural stage counting means including said first and second counting means for operating said first output device, control means including a second coincidence circuit having an element individual to and connected to each of said first counting means and said second counting means and responsive at each concurrence of different preselected discrete individual output indications from said plural stage counting means including said first and second counting means for operating said second output means, each of said control means further including settable switch means including a portion connected to each of said first and second counting means for selecting the count of each of said first and second counting means at which said preselected discrete output indications occur, and means controlled by one of said control means and effective only after said plural stage counting means has counted a number of said input signals equal to that required to cause said plural stage counting means to produce the larger of said preselected discrete output indication and said different preselected output indication for disabling said pulse means to produce said series of input signals.

3. A timing system for counting input pulses and for producing output indications at each of a plurality of preselected numbers of said pulses which are concurrently counted comprising a source of regularly recurring signals, pulsemeans connected to said source for producing a series of input signals from said regularly recurring signals, plural stage counting means responsive to said input signals for counting numbers as large as the largest of said preselected numbers comprising first counting means responsive to said input signals for repetitively and cyclically counting predetermined numbers of said input pulses and producing a discret individual output indication at each count and an output signal at each of said predetermined numbers of input pulses and second counting means connected to said first counting means for repetitively and cyclically counting predetermined numbers of said output signals and producing a discrete individual output indication at each count, first and second output devices, control means including a first coincidence circuit having an element individual to and connected to each of said first counting means and said second counting means and responsive at each concurrence of preselected discrete individual output indications from said plural stage counting means including said first and second counting means for operating said first output device, control means including a second coincidence circuit having an element individual to and connected to each of said first counting means and said second counting means and responsive at each concurrence of different preselected discrete individual output indications from said plural stage counting means including said first and second counting means for operating said second output means, and means effective only after said plural stage counting means has counted a number of said input signals at least equal to that required to cause said plural stage counting means to produce the larger of said preselected discrete output indication and said different preselected output indication for disabling said pulse means to produce said series of input signals, each of said control means comprising a source of direct voltage, a voltage dropping device connected to said source, a plurality of unidirectional current conducting devices each having one electrode connected to said voltage dropping device and each normally effective to conduct adequate current flowing from said source through said voltage dropping device to produce a voltage drop across said voltage dropping device greater than a preselected value, means for applying a discrete individual output indication from said first counting means representative of a preselected count to one of said devices for causing said one o f said devices to present an increased resistance to current flow through said voltage dropping de vice, means for applying a discrete individual output indication from said second counting means to the other one of said devices for causing said other one of said devices to present an increased resistance to current flow through said voltage dropping device, and means effective whenever the voltage drop across said voltage dropping device is less than said predetermined value for operating the associated output device.

4. The combination of claim 3 in which said last-men tioned means includes a thyratron, means for applying a hold-off potential to said thyratron, and means for connecting said voltage dropping device to the input circuit of said thyratron.

5. A timing system for counting input pulses and for producing an output indication at a preselected total count comprising a source of alternating current signals, an electron discharge device, means for producing a positive-going spike pulse at the peak of one half-cycle of each cycle of said alternating current, means for applying said spike pulses to said electron discharge device, means for disabling said electron discharge device effectively to respond to said spike pulses, initiating means, and means effective in response to said initiating means for enabling said electron discharge device at a time during the other half-cycle of said alternating current signal.

6. A timing system for counting input pulses and for producing an output indication at a preselected total count comprising a source of alternating current signals, an electron discharge device, means for producing a positive-going spike pulse at the peak of one half-cycle of each cycle of said alternating current, means for applying said spike pulses to said electron discharge device, means for disabling said electron discharge device effective to respond to said spike pulses, initiating means, means effective to said initiating means for enabling said electron discharge device at a time during the other half-cycle of said alternating current signal comprising a thyratron, means efiective when said thyratron is effective for applying a disabling voltage to said electron discharge device, a capacitor, means including said capacitor for applying a hold-01f voltage to the input circuit of said thyratron, means for applying to the input circuit of said thyratron an alternating voltage which is 180 out-of-phase with said alternating current signal, and means effective upon the actuation of said initiating means for discharging said capacitor at a time-controlled rate.

7. A timing system for counting input pulses and for producing output indications at each of a plurality of preselected numbers of said pulses comprising a source of regularly recurring signals, pulse means connected to said source for producing a series of input signals from said regularly recurring signals, first counting means responsive to said input signals 'for repetitively and cyclically counting predetermined numbers of said input pulses and producing a discrete individual output indication at each count and an output signal at each of said predetermined numbers of input pulses and second counting means connected to said first counting means for repetitively and cyclically counting predetermined numbers of said output signals and producing a discrete individual output indication at each count, first and second output devices, control means including a first coincidence circuit responsive only to the concurrent of preselected discrete individual output indications from said first and second counting means for operating said first output device, and control means including a second coincidence circuit responsive only to the concurrence of different preselected discrete individual output indications from said first and second counting means for operating said second output means, said regularly recurring signals being sinusoidal alternating current signals, said pulse means comprising an electron discharge device, means for producing a positivegoing spike pulse at the peak of one half-cycle of each cycle of said alternating current, means for applying said spike pulses to said electron discharge device, means for disabling said electron discharge device eifectively to respond to said spike pulses, initiating means, and means effective in response to said initiating means for enabling said electron discharge device at a time during the other half-cycle of said alternating current signal.

References Cited by the Examiner UNITED STATES PATENTS 2,519,184 8/50 Grosdofi 32848 2,970,303 1/61 Williams 32894 2,970,763 2/61 Greeman 328-48 2,972,718 2/61 Alperin et al 32848 2,975,338 3/61 Bivens et al 32848 ARTHUR GAUSS, Primary Examiner.

GEORGE N. WESTBY, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N05 3, 213,374 October 19, 1965 James A, Hawley It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 58, for "signals" read signal column 3, line 36, for "establishes" read establish line 66, after "negative" insert relative column 6, line 71, for "countnig" read counting M column 8, line 72, for "effective" read H effectively lines 73 and 74, after 'r' ffective" insert in response column 9, line 27, for "concurrent" read concurrence "h Signed and sealed this 19th day of July 1966,

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. A TIMING SYSTEM FOR COUNTING INPUT PULSES AND FOR PRODUCING OUTPUT INDICATIONS AT EACH OF A PLURALITY OF PRESELECTED NUMBERS OF SID PULSES WHICH ARE CONCURRENTLY COUNTED COMPRISING A SOURCE OF REGULARLY RECURRING SIGNALS, PULSE MEANS CONNECTED TO SAID SOURCE FOR PRODUCING A SERIES OF INPUT SIGNALS FROM SAID REGULARLY RECURRING SIGNALS, PLURAL STAGE COUNTING MEANS RESPONSIVE TO SAID INPUT SIGNALS FOR COUNTING NUMBERS AS LARGE AS THE LARGEST OF SAID PRESELECTED NUMBERS COMPRISING FIRST COUNTING MEANS RESPONSIVE TO SAID INPUT SIGNALS FOR REPETITIVELY AND CYCLICALLY COUNTING PREDETERMINED NUMBERS OF SAID INPUT PULSES AND PRODUCING A DISCRETE INDIVIDUAL OUTPUT INDICATION AT EACH COUNT AND AN OUTPUT SIGNAL AT EACH OF SAID PREDETERMINED NUMBERS OF INPUT PULSES AND SECOND COUNTING MEANS CONNECTED TO SAID FIRST COUNTING MEANS FOR REPETITIVELY AND CYCLICALLY COUNTING PREDETERMINED NUMBERS OF SAID OUTPUT SIGNALS AND PRODUCING A DISCRETE INDIVIDUAL OUTPUT INDICATION AT EACH COUNT, FIRST AND SECOND OUTPUT DEVICES, CONTROL MEANS INCLUDING A FIRST COINCIDENCE CIRCUIT HAVING AN ELEMENT INDIVIDUAL TO AND CONNECTED TO EACH OF SAID FIRST COUNTING MEANS AND SAID SECOND COUNTING MEANS AND RESPONSIVE AT EACH CONCURRENCE OF PRESELECTED DISCRETE INDIVIDUAL OUTPUT INDICATIONS FROM SAID PLURAL STAGE COUNTING MEANS INCLUDING SAID FIRST AND SECOND COUNTING MEANS INCLUDING OPERATING SAID FIRST OUTPUT DEVICE, CONTROL MEANS INCLUDING A SECOND COINCIDENCE CIRCUIT HAVING AN ELEMENT INDIVIDUAL TO AND CONNECTED TO EACH OF SAID FIRST COUNTING MEANS AND SAID SECOND COUNTING MEANS AND RESPONSIVE AT EACH CONCURRENCE OF DIFFERENT PRESELECTED DISCRETE INDIVIDUAL OUTPUT INDICATIONS FROM SAID PLURAL STAGE COUNTING MEANS INCLUDING SAID FIRST AND SECOND COUNTING MEANS FOR OPERATING SAID SECOND OUTPUT DEVICE, AND MEAND EFFECTIVE ONLY AFTER SAID PLURAL STAGE COUNTING MEANS HAD COUNTED A NUMBER OF SAID INPUT SIGNALS EQUAL TO THAT REQUIRED TO CAUSE SAID PLURAL STAGE COUNTING MEANS TO PRODUCE THE LARGER OF SID PRESELECTED DISCRETE OUTPUT INDICATION AND SAID DIFFERENT PRESELECTED OUTPUT INDICATION FOR DISALBING SAID PULSE MEANS TO PRODUCE SAID SERIES OF INPUT SIGNALS. 